Since announcing its Technical Preview of Office 15 back in January, most users have not used and there is no news about Office 15. Currently, it is antipated that office 15 beta would come in June. Also, the screnshots of Beta Refresh of Office 15 is leaked. The new Beta Refresh features colored window shadows, faster animations, and a newer more refined look and feel to the interface.

Take a look at the screenshots (http://www.forumswindows8.com/info/office-15-technical-preview-refresh-screenshots-leak-tipped-june-beta-257.html).